National and Subnational estimates for the United Kingdom

Identifying changes in the reproduction number, rate of spread, and doubling time during the course of the COVID-19 outbreak whilst accounting for potential biases due to delays in case reporting both nationally and subnationally in the United Kingdom. These results are impacted by changes in testing effort, increases and decreases in testing effort will increase and decrease reproduction number estimates respectively.

Table of Contents


Using data available up to the: 2020-10-25

Subnational and national estimates are available to download here.

See our see Methods or our paper for an explanation of how these estimates are derived.

Interactive summary


Figure 1: The results of the latest reproduction number estimates (based on estimated confirmed cases with a date of infection on the 2020-10-25) can be summarised by whether confirmed cases are likely increasing or decreasing. This represents the strength of the evidence that the reproduction number in each region is greater than or less than 1, respectively (see the methods for details). Click on a subnational area (or search) to see subnational level estimates. This interactive visualisation is powered by RtD3(Gibbs, Abbott, and Funk 2020).

National summary

Summary (estimates as of the 2020-10-25)

Table 1: Latest estimates (as of the 2020-10-25) of the number of confirmed cases by date of infection, the expected change in daily confirmed cases, the effective reproduction number, the growth rate, and the doubling time (when negative this corresponds to the halving time). The median and 90% credible interval is shown for each numeric estimate.
Estimate
New confirmed cases by infection date 29415 (14131 – 47533)
Expected change in daily cases Unsure
Effective reproduction no. 1.1 (0.8 – 1.3)
Rate of growth 0.03 (-0.04 – 0.09)
Doubling/halving time (days) 27.2 (7.6 – -17.1)

Confirmed cases, their estimated date of report, date of infection, and time-varying reproduction number estimates


Figure 2: A.) Confirmed cases by date of report (bars) and their estimated date of report. B.) Confirmed cases by date of report (bars) and their estimated date of infection. C.) Time-varying estimate of the effective reproduction number (lightest ribbon = 90% credible interval; darker ribbon = the 50% credible interval, darkest ribbon = 20% credible interval). Estimates from existing data are shown up to the 2020-10-25 from when forecasts are shown. These should be considered indicative only. Estimates based on partial data have been adjusted for right truncation of infections. The vertical dashed line indicates the date of report generation. Uncertainty has been curtailed to a maximum of ten times the maximum number of reported cases for plotting purposes.

Regional Breakdown

Data availability

Limitations

Summary of latest reproduction number and confirmed case count estimates by date of infection


Figure 3: Confirmed cases with date of infection on the 2020-10-25 and the time-varying estimate of the effective reproduction number (lightest ribbon = 90% credible interval; darker ribbon = the 50% credible interval, darkest ribbon = 20% credible interval). Regions are ordered by the number of expected daily confirmed cases and shaded based on the expected change in daily confirmedcases. The horizontal dotted line indicates the target value of 1 for the effective reproduction no. required for control and a single case required for elimination. Uncertainty has been curtailed to a maximum of ten times the maximum number of reported cases for plotting purposes.

Reproduction numbers over time in the six regions expected to have the most new confirmed cases


Figure 4: Time-varying estimate of the effective reproduction number (lightest ribbon = 90% credible interval; darker ribbon = the 50% credible interval, darkest ribbon = 20% credible interval) in the regions expected to have the highest number of new confirmed cases. Estimates from existing data are shown up to the 2020-10-25 from when forecasts are shown. These should be considered indicative only. Estimates based on partial data have been adjusted for right truncation of infections. The vertical dashed line indicates the date of report generation.

Confirmed cases and their estimated date of infection in the six regions expected to have the most new confirmed cases


Figure 5: Confirmed cases by date of report (bars) and their estimated date of infection (lightest ribbon = 90% credible interval; darker ribbon = the 50% credible interval, darkest ribbon = 20% credible interval) in the regions expected to have the highest number of new confirmed cases. Estimates from existing data are shown up to the 2020-10-25 from when forecasts are shown. These should be considered indicative only. Estimates based on partial data have been adjusted for right truncation of infections. The vertical dashed line indicates the date of report generation. Uncertainty has been curtailed to a maximum of ten times the maximum number of reported cases for plotting purposes.

Confirmed cases and their estimated date of report in the six regions expected to have the most new confirmed cases


Figure 6: Confirmed cases by date of report (bars) and their estimated date of report (lightest ribbon = 90% credible interval; darker ribbon = the 50% credible interval, darkest ribbon = 20% credible interval) in the regions expected to have the highest number of new confirmed cases. Estimates from existing data are shown up to the 2020-10-25 from when forecasts are shown. These should be considered indicative only. Estimates based on partial data have been adjusted for right truncation of infections. The vertical dashed line indicates the date of report generation. Uncertainty has been curtailed to a maximum of ten times the maximum number of reported cases for plotting purposes.

Reproduction numbers over time in all regions


Figure 7: Time-varying estimate of the effective reproduction number (lightest ribbon = 90% credible interval; darker ribbon = the 50% credible interval, darkest ribbon = 20% credible interval) in all regions. Estimates from existing data are shown up to the 2020-10-25 from when forecasts are shown. These should be considered indicative only. Estimates based on partial data have been adjusted for right truncation of infections. The horizontal dotted line indicates the target value of 1 for the effective reproduction no. required for control. The vertical dashed line indicates the date of report generation.

Confirmed cases and their estimated date of infection in all regions

Figure 8: Confirmed cases by date of report (bars) and their estimated date of infection (lightest ribbon = 90% credible interval; darker ribbon = the 50% credible interval, darkest ribbon = 20% credible interval) in all regions. Estimates from existing data are shown up to the 2020-10-25 from when forecasts are shown. These should be considered indicative only. Estimates based on partial data have been adjusted for right truncation of infections. The vertical dashed line indicates the date of report generation. Uncertainty has been curtailed to a maximum of ten times the maximum number of reported cases for plotting purposes.

Confirmed cases and their estimated date of report in all regions

Figure 9: Confirmed cases by date of report (bars) and their estimated date of report (lightest ribbon = 90% credible interval; darker ribbon = the 50% credible interval, darkest ribbon = 20% credible interval) in all regions. Estimates from existing data are shown up to the 2020-10-25 from when forecasts are shown. These should be considered indicative only. Estimates based on partial data have been adjusted for right truncation of infections. The vertical dashed line indicates the date of report generation. Uncertainty has been curtailed to a maximum of ten times the maximum number of reported cases for plotting purposes.

Latest estimates (as of the 2020-10-25)

Table 2: Latest estimates (as of the 2020-10-25) of the number of confirmed cases by date of infection, the effective reproduction number, the rate of growth, and the doubling time (when negative this corresponds to the halving time) in each region. The median and 90% credible interval is shown.

Comparison of cases, admissions, and deaths data

Using Rt to explore transmission in vulnerable populations

We calculate Rt as the average of how many new infections arise from one infected person. But who is the “average” infected person? We only measure a Covid-19 infection when someone gets tested, admitted to hospital, or dies after disease has been confirmed. However, none of these data sources is truly representative of all the infections that have occurred. For example, patients in hospital are more likely to be vulnerable to severe disease (e.g. older or immunocompromised), compared to the average in the general population. This means that each data source represents a slightly different type of “average” person who has been infected.

We can use this feature of each data source to explore how transmission is spreading in different parts of the population. For example, in the UK in August, most new infections were spread between young people, typically less vulnerable to severe disease. This meant the Rt from all test-positive cases rose quicker over that period than the Rt calculated from patients in hospital.

By tracking these comparisons, we can understand how Covid-19 is affecting the most vulnerable populations. To see this more clearly, we plot and compare Rt estimates from each data source.

To explore in more depth how Rt from different data sources can be used to understand transmission dynamics across the population, see our pre-print (currently in peer-review) here.

Figure 10: Estimates of Rt (median, with 50% (darker shade) and 90% (lightest shade) credible interval), derived from data sources including all test-positive cases, hospital admissions, and deaths with a positive test in the previous 28 days.

Table 3: Latest estimates of Rt, derived from data sources including all test-positive cases, hospital admissions, and deaths with a positive test in the previous 28 days. The median and 90% credible interval is shown. Latest dates vary for cases (2020-11-07), admissions (2020-11-09), and deaths (2020-10-31).

Abbott, Sam, Katharine Sherratt, Jonnie Bevan, Hamish Gibbs, Joel Hellewell, James Munday, Patrick Barks, Paul Campbell, Flavio Finger, and Sebastian Funk. 2020. “Covidregionaldata: Subnational Data for the Covid-19 Outbreak.” - - (-): –. https://doi.org/10.5281/zenodo.3957539.

“Coronavirus (Covid-19) Cases in the Uk.” 2020. Public Health England. https://coronavirus.data.gov.uk/.

Gibbs, Hamish, Sam Abbott, and Sebastian Funk. 2020. “RtD3: Rt Visualization in D3.” Zenodo - (-): –. https://doi.org/10.5281/zenodo.4011841.

White, Tom. 2020. “Coronavirus (Covid-19) Uk Historical Data.” https://github.com/tomwhite/covid-19-uk-data.

Xu, Bo, Bernardo Gutierrez, Sarah Hill, Samuel Scarpino, Alyssa Loskill, Jessie Wu, Kara Sewalk, et al. n.d. “Epidemiological Data from the nCoV-2019 Outbreak: Early Descriptions from Publicly Available Data.” http://virological.org/t/epidemiological-data-from-the-ncov-2019-outbreak-early-descriptions-from-publicly-available-data/337.